Rfid medical device control interface

ABSTRACT

A medical navigation system is provided for controlling medical equipment during a medical procedure. The medical navigation system includes a passive radio frequency identification (RFID) tag, an RFID sensor for detecting the passive RFID tag, a controller coupled to the RFID sensor, and a robotic arm having an end effector and controlled by the controller. The RFID sensor provides a signal to the controller indicating presence of an activated passive RFID tag. The passive RFID tag has an antenna, an RFID circuit, and a switching device coupled to the RFID circuit for activating the passive RFID tag. The passive RFID tag is used to control a payload attached to the end effector.

CROSS-REFERENCE

The present application is a continuation of U.S. patent applicationSer. No. 15/813,761 filed Nov. 15, 2017, which itself is a continuationof U.S. patent application Ser. No. 14/873,814, filed on Oct. 2, 2015(granted as U.S. Pat. No. 9,833,294 on Dec. 5, 2017), the contents ofeach are incorporated herein by reference.

TECHNICAL FIELD

The present disclosure is generally related to medical procedures, andmore specifically to an RFID medical device control interface.

BACKGROUND

Port-based surgery allows a surgeon, or robotic surgical system, toperform a surgical procedure involving tumor resection in which theresidual tumor remaining after is minimized, while also minimizing thetrauma to the intact white and grey matter of the brain. In suchprocedures trauma may occur, for example due to contact with the accessport, stress to the brain matter, unintentional impact with surgicaldevices, and/or accidental resection of healthy tissue.

Minimally invasive brain surgery using access ports is a recentlyconceived method of performing surgery on brain tumors previouslyconsidered inoperable. To address intracranial surgical concerns,specific products such as the NICO BrainPath™ port have been developedfor port-based surgery.

Referring to FIG. 1, the insertion of an access port into a human brainis shown for providing access to internal brain tissue during a medicalprocedure. In FIG. 1, access port 100 is inserted into a human brain 12,providing access to internal brain tissue. Surgical tools andinstruments may then be inserted within the lumen of the access port inorder to perform surgical, diagnostic or therapeutic procedures, such asresecting tumors as necessary.

As seen in FIG. 1, port 100 comprises of a cylindrical assembly formedof an outer sheath. Port 100 may accommodate an introducer which is aninternal cylinder that slidably engages the internal surface of port100. The introducer may have a distal end in the form of a conicalatraumatic tip to allow for insertion into the sulcal folds of the brain12. Port 100 has a sufficient diameter to enable bimanual manipulationof surgical tools within its annular volume such as suctioning devices,scissors, scalpels, and cutting devices.

Referring to FIG. 2, an exemplary navigation system is shown to supportsurgery, which in one example could be a minimally invasive accessport-based surgery. As shown in FIG. 2, a surgeon 103 conducts surgeryon a patient 120 in an operating room (OR) environment. A navigationsystem 107 comprising an equipment tower, tracking system, displays andtracked instruments assists the surgeon 103 during his procedure. Anoperator 121 is also present to operate, control and provide assistancefor the navigation system 107.

A foot pedal 155 is placed near the surgeon's foot and is utilized toactuate different elements during the procedure. For example, foot pedal155 may be used to lift or lower the surgical bed, or control zoom ofthe navigation system 107 or tracking system. In certain instances,multiple foot pedals may be deployed.

Conventional foot pedals used by a surgeon during a surgical procedure,particularly when multiple foot pedals are used, can be a distracting,given the surgeon must sometimes remove his focus from the surgicalfield of interest, resulting in the surgeon having to reorient himselfwhen his attention is returned. Further, by manipulating the foot pedal,the surgeon may lose concentration and/or focus of the surgicalprocedure at hand. Further, conventional foot pedals have wires attachedthereto for communication and power supply, which creates trippinghazards. There is an opportunity for improvement in the area of surgicalcontrols. There is a need for mechanism to provide improvedfunctionality and replacement of the foot pedal and other conventionalmedical control devices. There is a need for a medical control devicethat can be used in multiple locations, is not expensive to manufacture,does not create hazards in the operating room, and can be manufacturedin various forms.

SUMMARY

One aspect of the present description provides a medical navigationsystem for controlling medical equipment during a medical procedure. Themedical navigation system includes a passive radio frequencyidentification (RFID) tag, an RFID sensor for detecting the passive RFIDtag, a controller coupled to the RFID sensor, and a robotic arm havingan end effector and controlled by the controller. The RFID sensorprovides a signal to the controller indicating presence of an activatedpassive RFID tag. The passive RFID tag has an antenna, an RFID circuit,and a switching device coupled to the RFID circuit for activating thepassive RFID tag. The passive RFID tag is used to control a payloadattached to the end effector.

The switching device may also be coupled to the antenna and includes amechanical switch that connects and disconnects the antenna from theRFID circuit, thereby activating and deactivating the passive RFID tag.

The antenna may instead or further be coupled to the RFID circuit andthe passive RFID tag transmits a first identification (ID) and theswitching device includes a mechanical switch that changes thetransmitted ID to a second ID when the switch is pressed.

A further understanding of the functional and advantageous aspects ofthe disclosure can be realized by reference to the following detaileddescription and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments will now be described, by way of example only, withreference to the drawings, in which:

FIG. 1 illustrates the insertion of an access port into a human brain,for providing access to internal brain tissue during a medicalprocedure;

FIG. 2 shows an exemplary navigation system to support image guidedsurgery;

FIG. 3 is a diagram illustrating components of an exemplary surgicalsystem used in image guided surgery;

FIG. 4 illustrates various foot pedals and foot positioning of surgeonsduring commonly performed neurosurgeries;

FIG. 5A illustrates operation of a conventional passive RFID tag;

FIG. 5B illustrates operation of an RFID medical control deviceaccording to one aspect of the present application;

FIG. 5C illustrates operation of multiple RFID medical control devicesof FIG. 5B; and

FIG. 6 is block diagram showing an exemplary navigation system orsurgical system which may be used with the RFID medical control deviceshown in

FIGS. 5B and 5C.

DETAILED DESCRIPTION

Various embodiments and aspects of the disclosure will be described withreference to details discussed below. The following description anddrawings are illustrative of the disclosure and are not to be construedas limiting the disclosure. Numerous specific details are described toprovide a thorough understanding of various embodiments of the presentdisclosure. However, in certain instances, well-known or conventionaldetails are not described in order to provide a concise discussion ofembodiments of the present disclosure.

As used herein, the terms, “comprises” and “comprising” are to beconstrued as being inclusive and open ended, and not exclusive.Specifically, when used in the specification and claims, the terms,“comprises” and “comprising” and variations thereof mean the specifiedfeatures, steps or components are included. These terms are not to beinterpreted to exclude the presence of other features, steps orcomponents.

As used herein, the term “exemplary” means “serving as an example,instance, or illustration,” and should not be construed as preferred oradvantageous over other configurations disclosed herein.

As used herein, the terms “about” and “approximately” are meant to covervariations that may exist in the upper and lower limits of the ranges ofvalues, such as variations in properties, parameters, and dimensions. Inone non-limiting example, the terms “about” and “approximately” meanplus or minus 10 percent or less.

Unless defined otherwise, all technical and scientific terms used hereinare intended to have the same meaning as commonly understood to one ofordinary skill in the art. Unless otherwise indicated, such as throughcontext, as used herein, the following terms are intended to have thefollowing meanings:

As used herein the phrase “intraoperative” refers to an action, process,method, event or step that occurs or is carried out during at least aportion of a medical procedure. Intraoperative, as defined herein, isnot limited to surgical procedures, and may refer to other types ofmedical procedures, such as diagnostic and therapeutic procedures.

The use of switches in presently performed surgical procedures is auseful feature for convenient control of the surgical devices andsystems involved. However, presently available actuation devices resultin inefficiencies that must be overcome by the surgeon and/or surgicalteam. Examples of such inefficiencies will be described below.

There are many sources of ergonomic issues encountered during commonsurgeries shown using foot pedals. The use of foot pedals createsproblems associated with physical, perceptual, and cognitive use. Thepresent application aims to address these problems and others associatedwith presently used actuation or control devices.

In an ideal surgical procedure, a surgeon will minimize the amount oftime in which his focus is away from the surgical site of interest. Thisincludes minimizing the time during which the surgeon is not viewing thesurgical site of interest as well as the time during which the surgeonis not in the bimanual procedural position or any other potentialinstance which can be avoided to minimize the time required for thesurgery. When utilizing a foot pedal switch as described above,inefficiencies can be attributed to the situations described below.

Referring now to FIG. 3, a diagram is shown illustrating components ofan exemplary surgical system such as the medical navigation system 107used in port based surgery. Reference is also made to FIG. 4, whichshows various foot pedals and foot positioning of a surgeon duringcommonly performed surgeries. In one instance the surgeon may have toreposition one or more foot pedals 155 when he changes his orientationrelative to the patient during surgery, indicated by reference 300 (FIG.4). When this occurs, the surgeon's focus is removed from the surgicalarea of interest to correctly reposition the foot pedal 155. Inaddition, this may also require the surgeon to remove his tools from thebimanual procedural position as well.

During a medical procedure a surgeon may have to use the foot pedals 155in an inopportune (e.g., non-ergonomic) position. Various operatingstances can require the surgeon to position himself awkwardly andtherefore make the use of a pedal inefficient and difficult to do withaccuracy. In one example, the surgeon may be leaning over the patientrequiring the surgeon to fully extend his leg and even have to stand onhis toes. It is apparent that in such a stance the resulting positioningof the foot would make it difficult for the surgical personnel tooperate the foot pedal because in such a position the heel of the footwould be elevated from the ground. Even if the foot is located on theground, but is fully extended, the ball of the foot will be difficult touse in a flexion as it would be required for stability of the surgeon.Therefore, using the foot to operate the foot pedal in such a positionwould reduce the amount of precision when engaging the foot pedalthrough a plantar flexion movement. This situation may also require thesurgeon to move the pedal(s) 155 positioning on the floor of theoperating room resulting in increased time required for the surgicalprocedure and hence decreasing efficiency of the operation.

The surgeon may also have to use multiple foot pedals 155 during asurgical procedure requiring him to differentiate between foot pedalsthrough proprioception, estimated foot pedal placement knowledge, andhis sense of touch as opposed to knowing with a greater certainty thelocation of the pedal 155 he wants to actuate relative to his footposition. This estimation of pedal 155 location using touch andproprioception may also be inhibited by the wearing of shoes. If thesurgeon is unable to locate the pedal 155 using the three sensesmentioned, the surgeon will be again required to remove his focus fromthe surgical site of interest and his tools from the bimanual proceduralposition in order to do so. It should be noted that this is aconsequence of free placement of the pedals 155 on the floor, since thepedals 155 aren't placed at a “known” relative position (e.g., aposition relative to the surgical bed or area of interest) that thesurgeon could intuitively find using touch or proprioception knowledgein combination with previous surgical experience. Other issues inlocating and engaging the foot pedal(s) 155 may be caused when the footpedal 155 is placed under the surgical bed, where it would be out ofsite of the surgeon and may require the surgeon to spend more timelocating the pedal(s) 155 as opposed to being positioned in clear site.

At points during the surgery the surgeon may have to stand and utilizemotor functions in both his arms and legs to position a medical deviceand actuate it simultaneously using the foot pedal 155 respectively.This may be an inefficient way for the surgeon to operate a device asthe simultaneous actuation of a foot pedal 155 and precise arm movementis not an intuitive function for most individuals.

The use of a foot pedal 155 in a surgical procedure may also imposeadditional wiring on the floor of the surgical suite, resulting inincreased tripping hazards in the operating room, which are dangerousand may cause serious harm to the patient if surgical personnel were totrip over such wiring.

An alternate procedural element actuation device utilizes a tool with anattached or integrated switch such as the Stryker Smart Instruments.When using such a tool, inefficiencies may occur in the followingcontexts. The tool may have a limit on its available area for a givenuser interface control containing switches for manipulation of elementsused during the surgical procedure. Reasons for such limits relate tothe user interface being integrated into the tool as opposed to aseparate control user interface. Since surgical tools are preciseinstruments to be manipulated by the surgeon, their weights, sizes, andoverall features greatly affect the dexterity of the surgeon. Therefore,increasing the size of the user interface control area for more numerousand/or larger more easily identifiable and accessible buttons may resultin heftier instruments again reducing the precision of the surgeon whenusing the tool. Additionally, when tools are engaged in minimallyinvasive surgeries, the tools must be manipulated within a smallcorridor. In this context increasing the size of the tool may not befeasible as it may occlude the view down the corridor or become toolarge as to restrict access of the tool into the corridor. Alternateissues are associated with placing an electronic user interface on asurgical tool. The electronics must be designed to withstand commonlyused sterilization processes. Viable ways of achieving such an abilityto withstand sterilization require the electronics to be bulkier andheavier than their non-integrated counterparts (e.g., the tool withoutthe user interface controller) as sterilization occurs at hightemperatures and pressures. Specifically, when sterilizing medicalinstruments using the autoclaving technique the instruments mustwithstand temperatures of 121C-190C and pressures of 15 psi-40 psi.

The manufacture and purchase of tools with built in user interfaces isalso problematic. Multiple surgical tools each having a built in userinterface (UI), for example, both a resection tool and bipolar pituitaryforceps, to be used within a surgical procedure will likely be morecostly than having a single surgical glove interface that can beintegrated with all potential tools the surgeon may use. An advantage tousing a single entity surgical glove interface disclosed herein is thatthe surgical glove interface may be configured to adaptively switchoutput selection such that the detection of the tool being used by thesystem sets the output of each of the buttons, as opposed to having aseparate user interface on each medical tool as would be required by asurgical tool with a built in user interface.

When utilizing a kinect based gesture control user interface to controlsurgical procedural elements, inefficiencies can occur in the followingcontexts. Such a user interface control requires the surgeon to removehis hands from the bimanual procedural position when performing thegestures required to control the user interface. In addition to thisrequirement, the surgeon must perform an initial gesture to initiate theKinect sensors and begin controlling the user interface which in turnincreases the time required for the surgery as opposed to being able toconstantly control the interface. A consequence of this user interfacecontrol system is that the surgeon has to remove his attention from thesurgical site of interest (or equivalently a display of the surgicalsite of interest) when performing gestures to control the system. Thisresults in the surgeon having to directionally reorient himself with thedisplay of the surgical site of interest with respect to the spatialorientation of the patient in the operating room when returning to thebimanual procedural position, which will also result in an increase ofthe total time of the surgical procedure. Since the Kinect sensor is adetector with an inherent field of view, the surgeon may additionallyhave to reposition himself away from his surgical procedural stance inorder to enter the correct field of view, to gain full control over thefunctionality of the user interface.

Referring back to FIG. 3, FIG. 3 illustrates a medical navigation system107 having an equipment tower 101, a tracking system 113, a display 111(e.g., to show a graphical user interface), an intelligent positioningsystem 175 and tracking markers 165 used to track medical instruments oran access port 100. Tracking system 113 may be considered an opticaltracking device or tracking camera.

In FIG. 3, a surgeon 103 is performing a tumor resection through a port100, using an imaging device 104 to view down the port at a sufficientmagnification to enable enhanced visibility of the instruments andtissues. The imaging device 104 may be an exoscope, videoscope, widefield camera, or an alternate image capturing device. The imaging sensorview is depicted on the visual display 111 which the surgeon 103 usesfor navigating the port's distal end through the anatomical region ofinterest. The foot pedal 155 is located in an accessible vicinity to thesurgeon's foot and is utilized to actuate an element used in theprocedure.

The intelligent positioning system 175 receives as input the spatialposition and pose data of the automated arm 102 and target (for examplethe port 100) as determined by tracking system 113 by detection of thetracking markers 165 on the wide field camera 106 and the port 100.

The foot pedal 155 is located in an accessible vicinity to the surgeon'sfoot. Foot pedal 155 may be used to actuate an element used in theprocedure such as a neurosurgical drill, an illumination source,automated arm movement, a UI configuration, a resection device, anirrigation device, an imaging procedure, an imaging acquisition, achange of phase during surgery, or any other element requiring actuationduring a surgical procedure. Foot pedal 155 may have multiple activationinput configurations or modes as described in the following examples.

A first input configuration (or first mode) includes a binary switchmode in which a press of foot pedal 155 causes the foot pedal 155 tooutput a signal which actuates the state of a procedural element from“on” to “off” position. A second input configuration (or second mode) isa variable switch mode in which the output signal of the foot pedal isproportional to the degree of force applied to the pedal by the user. Athird input configuration (or third mode) may be a multiple switch modein which a press of the foot pedal cycles the element through variousmodes of function (i.e. modes of function of the element). It should benoted that all switches mentioned in this disclosure can be formed ofany mechanism to allow for control of or actuation of a device.

These input configurations can also be implemented in combinationsprovided the system utilizes more than one foot pedal as shown as 310 inFIG. 4. For example, given two foot pedals as shown in FIG. 4,combinations can be two binary switches, in which the combinedactivation of both foot pedals can result in an alternate output fromthe output of each foot pedal activated individually. Another examplecombination using two foot pedals can be two multiple switch modes inwhich the foot pedal outputs when both are activated can be differentfrom when the pedals are activated individually. Another example usingtwo foot pedals would be a binary switch and a multiple switch in whichthe output of the activation of both foot pedals may be different thanwhen the pedals are activated individually.

According to one aspect of the present description, the finger of asurgeon may be used with a modified passive RFID tag that only activateswhen the device is pressed (e.g., when a button on the device ispressed).

Referring to FIG. 5A, operation of a conventional passive RFID tag isshown, indicated by reference 500. A conventional passive RFID tag 502activates when receiving an RF signal (indicated by reference 501) froman RFID reader or receiver 504. The RF signal 501 powers the passive tag502, which then responds with its identification (ID, indicated byreference 503), which is received by receiver 504.

Referring to FIG. 5B, an exemplary operation of an RFID medical controldevice interface, indicated by reference 510, according to one aspect ofthe present application is illustrated. The conventional passive RFIDtag 502 may be modified to change the circuit such that modified passiveRFID tag 512 can only respond accurately when a button 514 is pressed.In the top half of FIG. 5B, receiver 516 transmits transmission 511.Button 514 is not pressed, so RFID tag 512 does not respond to RF signaltransmission 511. In one example, button 514 may be a mechanical buttonincluded in an RFID circuit such that the circuit only functions whenthe button 514 is pressed. In another example, the button 514 orswitching device may take advantage of the finger's capacitance toadjust the frequency properties of the RFID tag 512 so that the RFID tag512 only reaches the correct transmission frequency when the finger isin contact with button 514. In the bottom half of FIG. 5B, button 514 ispressed, so RFID tag 512 responds to RF signal transmission 511 with IDtransmission 513. RF receiver 516 then recognizes the button press asthe RFID tag 512 transmits its ID. In another example, the RFID tag 512may send a first ID when the button 514 is not pressed and a seconddifferent ID when the button 514 is pressed.

The button 514 forming part of RFID tag 512 may be applied to anysurface, such as a finger, a wrist, a tool, a chair, etc. In oneexample, the RFID tag 512 may be placed on a pointer tool which, whencombined with the tracking mechanisms of the navigation system 507, mayprovide for movement of the pointer tool to be tracked and function as avirtual mouse for the surgeon to move a mouse on a screen, when thebutton 514 is activated. In another example, the RFID tag 512 may be asimple disposable sticker that could be applied pre-surgery.

FIG. 5C illustrates operation of multiple RFID medical control devices,indicated by 512 a . . . 512 n, or collectively as 512. While two RFIDmedical control devices 512 a and 512 n are shown in the example, anysuitable number may be used according to the design criteria of aparticular application, as denoted by n in 512 n. Multiple RFID tags 512a-n may be used within the same surgery. Given the flexibility of usinga sticker form of the RFID tag 512, surgeons may develop their ownpreferences on where they stick the tags 512.

In FIG. 5C, receiver 516 transmits transmission 511. Button 514 a is notpressed, so RFID tag 512 a does not respond to RF signal transmission511. However, button 514n of passive RFID tag 512 n is pressed, so RFIDtag 512 n responds to RF signal transmission 511 with ID transmission513 n. RF receiver 516 then recognizes the button press as the RFID tag512 n transmits its ID. In one example, the RF receiver 516 is coupledto navigation system 507 and the system 507 may be configured tointerpret a positive command only when more than one tag 512 is active.For example, there may be two RFID tags 512 a and 512 b and the user mayhave to press the button 514 on each of RFID tag 512 a and 512b before acorresponding function of navigation system 507 is activated.

In another example, the RFID tags 512 may be made active by adding abattery. While this would make the RFID tag 512 more expensive, it wouldreduce the signal levels of the RF receiver 516, which might bedesirable in some applications.

The use of the RFID tag 512 described in connection with FIGS. 5B-5C mayeliminate the need for the surgeon to utilize his eyes to locate aswitch, such as in the case of foot pedals 155 and the tool integratedcontroller user interface as described above, as the RFID tag 512 may belocated in an easily accessible vicinity to the surgeon's handthroughout the performance of the surgery. In contrast, both the use ofthe foot pedal and the tool integrated user interface would require thesurgeon to estimate the relative location of the switches on the footpedal and the tool respectively relative to the engaging body part(e.g., the surgeon's foot and finger(s) respectively) in addition tousing proprioception. The use of the RFID tags 512 may alsosubstantially reduce or eliminate the need for the surgeon to retractthe tools from the bimanual procedural position prematurely during thesurgery to allow for control of the user interface, such as when usingthe Kinect user interface controller.

As mentioned above, having a tool integrated user interface controllerdecreases the tool's precision as a result of various dimensionalconsiderations such as size of an access corridor in a minimallyinvasive surgery, increased dimensions of the tool, such as weight,height, length, width, etc. In contrast, when using the passive RFID tag512, the interface may be situated on the palm of the surgeon, andtherefore adding or reducing the features of the interface, such as atouch pad (described below), buttons, etc., do not affect the precisionof the tool being used. In addition, the palm of a surgeon willgenerally have more available space in comparison to a surgical toolhandle (e.g., without integrated user interface controller) allowing fora larger user interface controller area.

When presently performing surgery many surgeons utilize a foot pedalwhile simultaneously maneuvering their surgical tools in the surgicalarea of interest, for example when resecting a tumor a surgeon willcontrol the removal rate of the resection device with his foot and theresection device's position in the surgical area of interest with hishand, inclusive of the arm. In general, a surgeon's fingers are moreagile and precise in applying force than his foot. The passive RFID tag512 takes advantage of this fact and allows both the positioning of thetool and its control user interface (where passive RFID tag 512 is usedfor this purpose) to be managed by the hand of an individual surgeon.Also, since passive RFID tag 512 does not have to be located on theground, the additional hazardous wiring mentioned above will bealleviated in the operating room.

Referring to FIG. 6, a block diagram is shown illustrating an exemplarymedical navigation system 600 that may be used in the systems shown inFIGS. 2 and 3, and may also be used with the RFID tag 512 shown in FIGS.5B-C. An example embodiment of a medical navigation system 600 inclusiveof the RFID tag 512 disclosed herein is provided in FIG.6 in blockdiagram form.

FIG. 6 shows part of a medical navigation system 600. The medicalnavigation system 600 includes a passive radio frequency identification(RFID) tag 512. The passive RFID tag 512 has an antenna 530, an RFIDcircuit 532, and a switching device 534 coupled to the antenna 530and/or the RFID circuit 532 for activating the passive RFID tag 512. Themedical navigation system 600 further has an RFID sensor 612 fordetecting the passive RFID tag512 and a controller 660 coupled to theRFID sensor 612. The RFID sensor 612 provides a signal to controller 660indicating presence of an activated passive RFID tag. Depending on thedesign criteria of a particular application, the switching device 534may be coupled to both the antenna 530 and the RFID circuit 532 tointerrupt the pathway to the antenna 530 or just to the RFID circuit 532as a means of providing an input to the RFID circuit 532. Likewise, theantenna 530 may be directly coupled to the RFID circuit 532, coupledonly through the switching device 534 to the RFID circuit 532, or both,depending on the design criteria of a particular application.

In one example, the switching device 534 may include a mechanical switchthat connects and disconnects the antenna 530 from the RFID circuit 532,thereby activating and deactivating the passive RFID tag 512. In anotherexample, the passive RFID tag 512 transmits a first identification (ID)and the switching device 534 includes a mechanical switch that changesthe transmitted ID to a second ID when the switch is pressed. In oneexample, the passive RFID tag 512 may continue to transmit the second IDafter the switch is depressed and until the switch is pressed again. Inanother example, the passive RFID tag 512 reverts to transmitting thefirst ID when the switch is depressed.

In yet another example, the switching device 534 may include a touchsensor controllable by proximity to human skin. The switching device 534may adjust frequency properties of the passive RFID tag 512 such thatthe passive RFID tag 512 operates at an operational frequency when humanskin is in contact with the switching device 534.

The medical navigation system 600 has a tracked medical tool 645 thatmay have the passive RFID tag 512 mounted thereon. In another example,the passive RFID tag 512 may be enclosed in or attached to a stickersuch that the passive RFID tag 512 can be adhered to any surface in anoperating room environment. In another example, a collar wearable arounda finger may have the passive RFID tag 512 enclosed therein or attachedthereon. In another example, when the skin comes into close proximityand/or contact with the touch sensor, the antenna 530 may be detuned andthe RFID tag 512 may not operate at an operational frequency when thetouch sensor is being touched. In other words, the RFID tag 512 maytransmit an ID when the touch sensor is not being touched and the RFIDtag 512 may stop transmitting the ID when the touch sensor is touched.However, depending on the design criteria of a particular application,the RFID tag 512 may also be configured to not transmit an ID when thetouch sensor is not being touched and the RFID tag 512 may begintransmitting the ID when the touch sensor is touched.

In one example, data may be written to the RFID tag 512 during a medicalprocedure to encode some data such as how many times a certain tool isused (e.g., when the tag 512 is on the tool 645), if the tool iscalibrated or not, and/or what procedure was done with the tool. Thedata to be written to the RFID tag 512 may be provided by the navigationsystem 600.

In one example, the medical navigation system 600 includes a roboticarm, such as automated arm 102 (FIG. 3) indicated by reference 635 inFIG. 6, controlled by the controller 660. The passive RFID tag 512 maybe used to control a payload attached to an end effector of the roboticarm. The payload may be anything from the group such as a camera, an OCTsystem, an imaging system, an imaging device, a microscopy device, anexoscope, a display device, an optical coherence tomography (OCT)device, a spectrometry device, or any other suitable device. In oneexample, there may be a plurality of the passive RFID tags 512 in use inan operating room environment. The passive RFID tag 512 may bedisposable and/or wearable under a surgical glove. In the case where aplurality of passive RFID tags 512 is used, each of the plurality ofpassive RFID tags 512 may each have a distinct physical pattern usableto differentiate between the plurality of passive RFID tags 512 usingtouch.

FIG. 6 illustrates other control devices such as switching input device620. When a switch 615 is triggered, switch 615 provides a controlsignal 675, which corresponds to a command to the controller 622. Thecontroller 622 then encodes the control signal 675 into a digital signal623 and relays this digital signal to the wireless communicationsinterface 605. This signal is then encoded and relayed by the wirelesscommunications interface 605 over a radio frequency wirelesscommunication channel 680 using, for example, Bluetooth protocol. Theoutput signal is then received by a wireless interface 610, which in oneexample may be a Bluetooth transceiver employing the Bluetooth protocol,and is decoded and relayed to the medical navigation system controller660. The medical navigation system controller 660 then reads the controlsignal 675 and outputs the corresponding control signals 665 to thevarious devices used in the medical procedure. While a Bluetoothprotocol is provided as an example, any suitable wireless communicationssystem and protocol may be used to meet the design criteria of aparticular application, such as Wi-Fi, irDA, Zigbee, or any othersuitable system and/or protocol. Any of the components described inconnection with switching device 620 may optionally be integrated intopassive RFID tag 512, even power supply 625, which would make passiveRFID tag 512 an active RFID tag.

The medical navigation system 600 may further interface with trackedtools 645 and control optical electronics or light sources 655 usingcontrol signal 666 provided to the optical payload 650.

An exemplary surgical tool that is commonly utilized in surgery is thebipolar forceps (e.g., electrocautery device), with which a surgeon isable to cauterize vital blood vessels to prevent excessive bleeding. Acommand that can be actuated using the passive RFID tag 512 would be toactivate the forceps for cauterization, such as by applying a voltageacross the separated tips. A second commonly used surgical tool would bea resection device. The passive RFID tag 512 can be used to implementcommands to this device such as the implemented suction force andwhether the device is in tissue removal mode (e.g., tissue removal bladeactivated) or tissue manipulation mode (e.g., tissue removal bladedeactivated). The suction force command will determine at what ratetissue will be resected by the device while the removal mode commandwill indicate to the device to cut the tissue or not. The resection toolcommands are analogous to the third surgical tool, the neurosurgicaldrill, which may also be controlled by the passive RFID tag 512 by thesurgeon. Commands for this device may turn the drill on and off and mayalso dictate the speed of the drill as to minimize trauma to the patientin the form of vibrational pressure and increase the drill'seffectiveness.

Another exemplary surgical tool that may be controlled by the passiveRFID tag 512 is a Raman imaging probe. The passive RFID tag 512 may sendcommands via the controller 660 to this device to dictate itsacquisition rate, its acquisition area, its acquisition wavelength band,and when it acquires data.

The specific embodiments described above have been shown by way ofexample, and it should be understood that these embodiments may besusceptible to various modifications and alternative forms. It should befurther understood that the claims are not intended to be limited to theparticular forms disclosed, but rather to cover all modifications,equivalents, and alternatives falling within the spirit and scope ofthis disclosure.

1-20. (canceled)
 21. A system for controlling medical equipment during amedical procedure, comprising: a passive radio frequency identification(RFID) tag configured to control the medical equipment and having: anantenna; an RFID circuit; and a switching device coupled to at least oneof the antenna or the RFID circuit for activating the passive RFID tag,the switching device comprising a touch sensor, the switching deviceconfigured to switch the passive RFID tag between transmission of afirst identification (ID) in response to an absence of a touch detectedby the touch sensor, and transmission of a second ID in response to thetouch detected by the touch sensor; an RFID sensor for detectingtransmissions from the passive RFID tag; and a controller coupled to theRFID sensor, the RFID sensor providing the first or second ID to thecontroller from the passive RFID tag, the controller configured tocontrol the medical equipment based on the first or second ID received.22. The system of claim 21, wherein the medical equipment is a surgicaltool, and the passive RFID tag is mounted on the surgical tool.
 23. Thesystem of claim 22, wherein: the surgical tool is a pair of forceps, andthe passive RFID tag is configured to control the pair of forceps forperforming cauterization; the surgical tool is a resection device, andthe passive RFID tag is configured to control the resection device forperform suction, tissue removal or tissue manipulation; the surgicaltool is a drill, and the passive RFID tag is configured to controloperation of the drill; or the surgical tool is a Raman imaging probe,and the passive RFID tag is configured to control the probe for dataacquisition.
 24. The system according to claim 21, wherein the switchingdevice is coupled to both the antenna and the RFID circuit, theswitching device configured to connect or disconnect the antenna fromthe RFID circuit, thereby activating or deactivating the passive RFIDtag.
 25. The system according to claim 21, wherein the switching deviceis configured to operate the passive RFID tag at an operationalfrequency in response to the touch detected by the touch sensor, thepassive RFID tag experiencing a change in at least one frequencyproperty in response to the touch detected by the touch sensor.
 26. Thesystem according to claim 21, wherein the passive RFID tag is providedin a form that is wearable around a finger.
 27. The system according toclaim 21, wherein there are a plurality of passive RFID tags in use inan operating room environment, and the plurality of passive RFID tagseach has a distinct tactile pattern.
 28. A medical system comprising: acontroller; at least one passive RFID tag including: an antenna; an RFIDcircuit; and a switching device coupled to at least one of the antennaor the RFID circuit for activating the passive RFID tag, the switchingdevice comprising a touch sensor, the switching device configured toswitch the passive RFID tag between transmission of a firstidentification (ID) in response to an absence of a touch detected by thetouch sensor, and transmission of a second ID in response to the touchdetected by the touch sensor; an RFID sensor for detecting transmissionsfrom the passive RFID tag, the RFID sensor coupled to the controller totransmit the first or second ID from the passive RFID tag to thecontroller; at least one medical equipment; the controller configured tooutput a control signal to control operation of the at least one medicalequipment, based on the first or second ID received from the passiveRFID tag.
 29. The system according to claim 28, comprising a pluralityof passive RFID tags, wherein each passive RFID tag is associated with arespective unique identifier (ID) to enable the controller todistinguish between the unique IDs from different passive RFID tags. 30.The system according to claim 28, comprising a plurality of passive RFIDtags, wherein the controller is configured to output the control signalwhen more than one passive RFID tag is activated.
 31. The systemaccording to claim 28, wherein the controller is configured to writedata to the passive RFID tag, the data being related to the medicalequipment controlled based on the ID from the passive RFID tag.
 32. Thesystem according to claim 31, wherein the data written to the passiveRFID tag includes at least one of: number of times the medical equipmentis used, whether the medical equipment is calibrated, or what procedurewas performed using the medical equipment.
 33. A method for controllingmedical equipment during a medical procedure, the method comprising:receiving a radio-frequency (RF) signal with a passive radio frequencyidentification (RFID) tag having an antenna, an RFID circuit, and aswitching device coupled to at least one of the antenna or the RFIDcircuit, the switching device comprising a touch sensor; the passiveRFID tag transmitting a first identification (ID) to a controller inresponse to an absence of a touch detected by the touch sensor; thepassive RFID tag transmitting a second identification to the controllerin response to the touch detected by the touch sensor; wherein thecontroller controls operation of the medical equipment in response tothe first or second identification received from the passive RFID tag.34. The method of claim 33, further comprising operating the passiveRFID tag at an operational frequency in response to the touch detectedby the touch sensor, and changing at least one frequency property inresponse to the touch detected by the touch sensor.
 35. The method ofclaim 33, wherein the medical equipment is a surgical tool, the methodfurther comprising mounting the passive RFID tag onto the surgical tool.36. The method of claim 33, wherein the switching device is coupled toboth the antenna and the RFID circuit, the method further comprisingconnecting or disconnecting the antenna from the RFID circuit, therebyactivating or deactivating the passive RFID tag.
 37. The method of claim33, wherein the RF signal is received by a plurality of passive RFIDtags, the method further comprising each of the plurality of passiveRFID tags transmitting unique identifiers (IDs) to enable the controllerto distinguish between the unique IDs from different passive RFID tags.38. The method of claim 37, wherein the controller is configured tocontrol operation of the medical equipment in response to receivingmultiple unique identifiers from the plurality of passive RFID tags. 39.The method of claim 33, further comprising detecting the medicalequipment and, in response to the detection, setting an output inrelation to each button of the medical equipment.
 40. The method ofclaim 39, further comprising adaptively switching output selection witha surgical glove interface disposed within a surgical glove.